resources/src/mediawiki/mediawiki.Title.js

   1 /*!
   2  * @author Neil Kandalgaonkar, 2010
   3  * @author Timo Tijhof
   4  * @since 1.18
   5  */
   6
   7 ( function ( mw, $ ) {
   8         /**
   9          * Parse titles into an object structure. Note that when using the constructor
  10          * directly, passing invalid titles will result in an exception. Use #newFromText to use the
  11          * logic directly and get null for invalid titles which is easier to work with.
  12          *
  13          * Note that in the constructor and #newFromText method, `namespace` is the **default** namespace
  14          * only, and can be overridden by a namespace prefix in `title`. If you do not want this behavior,
  15          * use #makeTitle. Compare:
  16          *
  17          *     new mw.Title( 'Foo', NS_TEMPLATE ).getPrefixedText();                  // => 'Template:Foo'
  18          *     mw.Title.newFromText( 'Foo', NS_TEMPLATE ).getPrefixedText();          // => 'Template:Foo'
  19          *     mw.Title.makeTitle( NS_TEMPLATE, 'Foo' ).getPrefixedText();            // => 'Template:Foo'
  20          *
  21          *     new mw.Title( 'Category:Foo', NS_TEMPLATE ).getPrefixedText();         // => 'Category:Foo'
  22          *     mw.Title.newFromText( 'Category:Foo', NS_TEMPLATE ).getPrefixedText(); // => 'Category:Foo'
  23          *     mw.Title.makeTitle( NS_TEMPLATE, 'Category:Foo' ).getPrefixedText();   // => 'Template:Category:Foo'
  24          *
  25          *     new mw.Title( 'Template:Foo', NS_TEMPLATE ).getPrefixedText();         // => 'Template:Foo'
  26          *     mw.Title.newFromText( 'Template:Foo', NS_TEMPLATE ).getPrefixedText(); // => 'Template:Foo'
  27          *     mw.Title.makeTitle( NS_TEMPLATE, 'Template:Foo' ).getPrefixedText();   // => 'Template:Template:Foo'
  28          *
  29          * @class mw.Title
  30          */
  31
  32         /* Private members */
  33
  34         var
  35                 mwString = require( 'mediawiki.String' ),
  36
  37                 namespaceIds = mw.config.get( 'wgNamespaceIds' ),
  38
  39                 /**
  40                  * @private
  41                  * @static
  42                  * @property NS_MAIN
  43                  */
  44                 NS_MAIN = namespaceIds[ '' ],
  45
  46                 /**
  47                  * @private
  48                  * @static
  49                  * @property NS_TALK
  50                  */
  51                 NS_TALK = namespaceIds.talk,
  52
  53                 /**
  54                  * @private
  55                  * @static
  56                  * @property NS_SPECIAL
  57                  */
  58                 NS_SPECIAL = namespaceIds.special,
  59
  60                 /**
  61                  * @private
  62                  * @static
  63                  * @property NS_MEDIA
  64                  */
  65                 NS_MEDIA = namespaceIds.media,
  66
  67                 /**
  68                  * @private
  69                  * @static
  70                  * @property NS_FILE
  71                  */
  72                 NS_FILE = namespaceIds.file,
  73
  74                 /**
  75                  * @private
  76                  * @static
  77                  * @property FILENAME_MAX_BYTES
  78                  */
  79                 FILENAME_MAX_BYTES = 240,
  80
  81                 /**
  82                  * @private
  83                  * @static
  84                  * @property TITLE_MAX_BYTES
  85                  */
  86                 TITLE_MAX_BYTES = 255,
  87
  88                 /**
  89                  * Get the namespace id from a namespace name (either from the localized, canonical or alias
  90                  * name).
  91                  *
  92                  * Example: On a German wiki this would return 6 for any of 'File', 'Datei', 'Image' or
  93                  * even 'Bild'.
  94                  *
  95                  * @private
  96                  * @static
  97                  * @method getNsIdByName
  98                  * @param {string} ns Namespace name (case insensitive, leading/trailing space ignored)
  99                  * @return {number|boolean} Namespace id or boolean false
 100                  */
 101                 getNsIdByName = function ( ns ) {
 102                         var id;
 103
 104                         // Don't cast non-strings to strings, because null or undefined should not result in
 105                         // returning the id of a potential namespace called "Null:" (e.g. on null.example.org/wiki)
 106                         // Also, toLowerCase throws exception on null/undefined, because it is a String method.
 107                         if ( typeof ns !== 'string' ) {
 108                                 return false;
 109                         }
 110                         // TODO: Should just use local var namespaceIds here but it
 111                         // breaks test which modify the config
 112                         id = mw.config.get( 'wgNamespaceIds' )[ ns.toLowerCase() ];
 113                         if ( id === undefined ) {
 114                                 return false;
 115                         }
 116                         return id;
 117                 },
 118
 119                 /**
 120                  * @private
 121                  * @method getNamespacePrefix_
 122                  * @param {number} namespace
 123                  * @return {string}
 124                  */
 125                 getNamespacePrefix = function ( namespace ) {
 126                         return namespace === NS_MAIN ?
 127                                 '' :
 128                                 ( mw.config.get( 'wgFormattedNamespaces' )[ namespace ].replace( / /g, '_' ) + ':' );
 129                 },
 130
 131                 rUnderscoreTrim = /^_+|_+$/g,
 132
 133                 rSplit = /^(.+?)_*:_*(.*)$/,
 134
 135                 // See MediaWikiTitleCodec.php#getTitleInvalidRegex
 136                 rInvalid = new RegExp(
 137                         '[^' + mw.config.get( 'wgLegalTitleChars' ) + ']' +
 138                         // URL percent encoding sequences interfere with the ability
 139                         // to round-trip titles -- you can't link to them consistently.
 140                         '|%[0-9A-Fa-f]{2}' +
 141                         // XML/HTML character references produce similar issues.
 142                         '|&[A-Za-z0-9\u0080-\uFFFF]+;' +
 143                         '|&#[0-9]+;' +
 144                         '|&#x[0-9A-Fa-f]+;'
 145                 ),
 146
 147                 // From MediaWikiTitleCodec::splitTitleString() in PHP
 148                 // Note that this is not equivalent to /\s/, e.g. underscore is included, tab is not included.
 149                 rWhitespace = /[ _\u00A0\u1680\u180E\u2000-\u200A\u2028\u2029\u202F\u205F\u3000]+/g,
 150
 151                 // From MediaWikiTitleCodec::splitTitleString() in PHP
 152                 rUnicodeBidi = /[\u200E\u200F\u202A-\u202E]/g,
 153
 154                 /**
 155                  * Slightly modified from Flinfo. Credit goes to Lupo and Flominator.
 156                  * @private
 157                  * @static
 158                  * @property sanitationRules
 159                  */
 160                 sanitationRules = [
 161                         // "signature"
 162                         {
 163                                 pattern: /~{3}/g,
 164                                 replace: '',
 165                                 generalRule: true
 166                         },
 167                         // control characters
 168                         {
 169                                 // eslint-disable-next-line no-control-regex
 170                                 pattern: /[\x00-\x1f\x7f]/g,
 171                                 replace: '',
 172                                 generalRule: true
 173                         },
 174                         // URL encoding (possibly)
 175                         {
 176                                 pattern: /%([0-9A-Fa-f]{2})/g,
 177                                 replace: '% $1',
 178                                 generalRule: true
 179                         },
 180                         // HTML-character-entities
 181                         {
 182                                 pattern: /&(([A-Za-z0-9\x80-\xff]+|#[0-9]+|#x[0-9A-Fa-f]+);)/g,
 183                                 replace: '& $1',
 184                                 generalRule: true
 185                         },
 186                         // slash, colon (not supported by file systems like NTFS/Windows, Mac OS 9 [:], ext4 [/])
 187                         {
 188                                 pattern: new RegExp( '[' + mw.config.get( 'wgIllegalFileChars', '' ) + ']', 'g' ),
 189                                 replace: '-',
 190                                 fileRule: true
 191                         },
 192                         // brackets, greater than
 193                         {
 194                                 pattern: /[}\]>]/g,
 195                                 replace: ')',
 196                                 generalRule: true
 197                         },
 198                         // brackets, lower than
 199                         {
 200                                 pattern: /[{[<]/g,
 201                                 replace: '(',
 202                                 generalRule: true
 203                         },
 204                         // everything that wasn't covered yet
 205                         {
 206                                 pattern: new RegExp( rInvalid.source, 'g' ),
 207                                 replace: '-',
 208                                 generalRule: true
 209                         },
 210                         // directory structures
 211                         {
 212                                 pattern: /^(\.|\.\.|\.\/.*|\.\.\/.*|.*\/\.\/.*|.*\/\.\.\/.*|.*\/\.|.*\/\.\.)$/g,
 213                                 replace: '',
 214                                 generalRule: true
 215                         }
 216                 ],
 217
 218                 /**
 219                  * Internal helper for #constructor and #newFromText.
 220                  *
 221                  * Based on Title.php#secureAndSplit
 222                  *
 223                  * @private
 224                  * @static
 225                  * @method parse
 226                  * @param {string} title
 227                  * @param {number} [defaultNamespace=NS_MAIN]
 228                  * @return {Object|boolean}
 229                  */
 230                 parse = function ( title, defaultNamespace ) {
 231                         var namespace, m, id, i, fragment, ext;
 232
 233                         namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;
 234
 235                         title = title
 236                                 // Strip Unicode bidi override characters
 237                                 .replace( rUnicodeBidi, '' )
 238                                 // Normalise whitespace to underscores and remove duplicates
 239                                 .replace( rWhitespace, '_' )
 240                                 // Trim underscores
 241                                 .replace( rUnderscoreTrim, '' );
 242
 243                         // Process initial colon
 244                         if ( title !== '' && title[ 0 ] === ':' ) {
 245                                 // Initial colon means main namespace instead of specified default
 246                                 namespace = NS_MAIN;
 247                                 title = title
 248                                         // Strip colon
 249                                         .slice( 1 )
 250                                         // Trim underscores
 251                                         .replace( rUnderscoreTrim, '' );
 252                         }
 253
 254                         if ( title === '' ) {
 255                                 return false;
 256                         }
 257
 258                         // Process namespace prefix (if any)
 259                         m = title.match( rSplit );
 260                         if ( m ) {
 261                                 id = getNsIdByName( m[ 1 ] );
 262                                 if ( id !== false ) {
 263                                         // Ordinary namespace
 264                                         namespace = id;
 265                                         title = m[ 2 ];
 266
 267                                         // For Talk:X pages, make sure X has no "namespace" prefix
 268                                         if ( namespace === NS_TALK && ( m = title.match( rSplit ) ) ) {
 269                                                 // Disallow titles like Talk:File:x (subject should roundtrip: talk:file:x -> file:x -> file_talk:x)
 270                                                 if ( getNsIdByName( m[ 1 ] ) !== false ) {
 271                                                         return false;
 272                                                 }
 273                                         }
 274                                 }
 275                         }
 276
 277                         // Process fragment
 278                         i = title.indexOf( '#' );
 279                         if ( i === -1 ) {
 280                                 fragment = null;
 281                         } else {
 282                                 fragment = title
 283                                         // Get segment starting after the hash
 284                                         .slice( i + 1 )
 285                                         // Convert to text
 286                                         // NB: Must not be trimmed ("Example#_foo" is not the same as "Example#foo")
 287                                         .replace( /_/g, ' ' );
 288
 289                                 title = title
 290                                         // Strip hash
 291                                         .slice( 0, i )
 292                                         // Trim underscores, again (strips "_" from "bar" in "Foo_bar_#quux")
 293                                         .replace( rUnderscoreTrim, '' );
 294                         }
 295
 296                         // Reject illegal characters
 297                         if ( title.match( rInvalid ) ) {
 298                                 return false;
 299                         }
 300
 301                         // Disallow titles that browsers or servers might resolve as directory navigation
 302                         if (
 303                                 title.indexOf( '.' ) !== -1 && (
 304                                         title === '.' || title === '..' ||
 305                                         title.indexOf( './' ) === 0 ||
 306                                         title.indexOf( '../' ) === 0 ||
 307                                         title.indexOf( '/./' ) !== -1 ||
 308                                         title.indexOf( '/../' ) !== -1 ||
 309                                         title.slice( -2 ) === '/.' ||
 310                                         title.slice( -3 ) === '/..'
 311                                 )
 312                         ) {
 313                                 return false;
 314                         }
 315
 316                         // Disallow magic tilde sequence
 317                         if ( title.indexOf( '~~~' ) !== -1 ) {
 318                                 return false;
 319                         }
 320
 321                         // Disallow titles exceeding the TITLE_MAX_BYTES byte size limit (size of underlying database field)
 322                         // Except for special pages, e.g. [[Special:Block/Long name]]
 323                         // Note: The PHP implementation also asserts that even in NS_SPECIAL, the title should
 324                         // be less than 512 bytes.
 325                         if ( namespace !== NS_SPECIAL && mwString.byteLength( title ) > TITLE_MAX_BYTES ) {
 326                                 return false;
 327                         }
 328
 329                         // Can't make a link to a namespace alone.
 330                         if ( title === '' && namespace !== NS_MAIN ) {
 331                                 return false;
 332                         }
 333
 334                         // Any remaining initial :s are illegal.
 335                         if ( title[ 0 ] === ':' ) {
 336                                 return false;
 337                         }
 338
 339                         // For backwards-compatibility with old mw.Title, we separate the extension from the
 340                         // rest of the title.
 341                         i = title.lastIndexOf( '.' );
 342                         if ( i === -1 || title.length <= i + 1 ) {
 343                                 // Extensions are the non-empty segment after the last dot
 344                                 ext = null;
 345                         } else {
 346                                 ext = title.slice( i + 1 );
 347                                 title = title.slice( 0, i );
 348                         }
 349
 350                         return {
 351                                 namespace: namespace,
 352                                 title: title,
 353                                 ext: ext,
 354                                 fragment: fragment
 355                         };
 356                 },
 357
 358                 /**
 359                  * Convert db-key to readable text.
 360                  *
 361                  * @private
 362                  * @static
 363                  * @method text
 364                  * @param {string} s
 365                  * @return {string}
 366                  */
 367                 text = function ( s ) {
 368                         if ( s !== null && s !== undefined ) {
 369                                 return s.replace( /_/g, ' ' );
 370                         } else {
 371                                 return '';
 372                         }
 373                 },
 374
 375                 /**
 376                  * Sanitizes a string based on a rule set and a filter
 377                  *
 378                  * @private
 379                  * @static
 380                  * @method sanitize
 381                  * @param {string} s
 382                  * @param {Array} filter
 383                  * @return {string}
 384                  */
 385                 sanitize = function ( s, filter ) {
 386                         var i, ruleLength, rule, m, filterLength,
 387                                 rules = sanitationRules;
 388
 389                         for ( i = 0, ruleLength = rules.length; i < ruleLength; ++i ) {
 390                                 rule = rules[ i ];
 391                                 for ( m = 0, filterLength = filter.length; m < filterLength; ++m ) {
 392                                         if ( rule[ filter[ m ] ] ) {
 393                                                 s = s.replace( rule.pattern, rule.replace );
 394                                         }
 395                                 }
 396                         }
 397                         return s;
 398                 },
 399
 400                 /**
 401                  * Cuts a string to a specific byte length, assuming UTF-8
 402                  * or less, if the last character is a multi-byte one
 403                  *
 404                  * @private
 405                  * @static
 406                  * @method trimToByteLength
 407                  * @param {string} s
 408                  * @param {number} length
 409                  * @return {string}
 410                  */
 411                 trimToByteLength = function ( s, length ) {
 412                         return mwString.trimByteLength( '', s, length ).newVal;
 413                 },
 414
 415                 /**
 416                  * Cuts a file name to a specific byte length
 417                  *
 418                  * @private
 419                  * @static
 420                  * @method trimFileNameToByteLength
 421                  * @param {string} name without extension
 422                  * @param {string} extension file extension
 423                  * @return {string} The full name, including extension
 424                  */
 425                 trimFileNameToByteLength = function ( name, extension ) {
 426                         // There is a special byte limit for file names and ... remember the dot
 427                         return trimToByteLength( name, FILENAME_MAX_BYTES - extension.length - 1 ) + '.' + extension;
 428                 };
 429
 430         /**
 431          * @method constructor
 432          * @param {string} title Title of the page. If no second argument given,
 433          *  this will be searched for a namespace
 434          * @param {number} [namespace=NS_MAIN] If given, will used as default namespace for the given title
 435          * @throws {Error} When the title is invalid
 436          */
 437         function Title( title, namespace ) {
 438                 var parsed = parse( title, namespace );
 439                 if ( !parsed ) {
 440                         throw new Error( 'Unable to parse title' );
 441                 }
 442
 443                 this.namespace = parsed.namespace;
 444                 this.title = parsed.title;
 445                 this.ext = parsed.ext;
 446                 this.fragment = parsed.fragment;
 447         }
 448
 449         /* Static members */
 450
 451         /**
 452          * Constructor for Title objects with a null return instead of an exception for invalid titles.
 453          *
 454          * Note that `namespace` is the **default** namespace only, and can be overridden by a namespace
 455          * prefix in `title`. If you do not want this behavior, use #makeTitle. See #constructor for
 456          * details.
 457          *
 458          * @static
 459          * @param {string} title
 460          * @param {number} [namespace=NS_MAIN] Default namespace
 461          * @return {mw.Title|null} A valid Title object or null if the title is invalid
 462          */
 463         Title.newFromText = function ( title, namespace ) {
 464                 var t, parsed = parse( title, namespace );
 465                 if ( !parsed ) {
 466                         return null;
 467                 }
 468
 469                 t = Object.create( Title.prototype );
 470                 t.namespace = parsed.namespace;
 471                 t.title = parsed.title;
 472                 t.ext = parsed.ext;
 473                 t.fragment = parsed.fragment;
 474
 475                 return t;
 476         };
 477
 478         /**
 479          * Constructor for Title objects with predefined namespace.
 480          *
 481          * Unlike #newFromText or #constructor, this function doesn't allow the given `namespace` to be
 482          * overridden by a namespace prefix in `title`. See #constructor for details about this behavior.
 483          *
 484          * The single exception to this is when `namespace` is 0, indicating the main namespace. The
 485          * function behaves like #newFromText in that case.
 486          *
 487          * @static
 488          * @param {number} namespace Namespace to use for the title
 489          * @param {string} title
 490          * @return {mw.Title|null} A valid Title object or null if the title is invalid
 491          */
 492         Title.makeTitle = function ( namespace, title ) {
 493                 return mw.Title.newFromText( getNamespacePrefix( namespace ) + title );
 494         };
 495
 496         /**
 497          * Constructor for Title objects from user input altering that input to
 498          * produce a title that MediaWiki will accept as legal
 499          *
 500          * @static
 501          * @param {string} title
 502          * @param {number} [defaultNamespace=NS_MAIN]
 503          *  If given, will used as default namespace for the given title.
 504          * @param {Object} [options] additional options
 505          * @param {boolean} [options.forUploading=true]
 506          *  Makes sure that a file is uploadable under the title returned.
 507          *  There are pages in the file namespace under which file upload is impossible.
 508          *  Automatically assumed if the title is created in the Media namespace.
 509          * @return {mw.Title|null} A valid Title object or null if the input cannot be turned into a valid title
 510          */
 511         Title.newFromUserInput = function ( title, defaultNamespace, options ) {
 512                 var namespace, m, id, ext, parts;
 513
 514                 // defaultNamespace is optional; check whether options moves up
 515                 if ( arguments.length < 3 && $.type( defaultNamespace ) === 'object' ) {
 516                         options = defaultNamespace;
 517                         defaultNamespace = undefined;
 518                 }
 519
 520                 // merge options into defaults
 521                 options = $.extend( {
 522                         forUploading: true
 523                 }, options );
 524
 525                 namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;
 526
 527                 // Normalise additional whitespace
 528                 title = title.replace( /\s/g, ' ' ).trim();
 529
 530                 // Process initial colon
 531                 if ( title !== '' && title[ 0 ] === ':' ) {
 532                         // Initial colon means main namespace instead of specified default
 533                         namespace = NS_MAIN;
 534                         title = title
 535                                 // Strip colon
 536                                 .substr( 1 )
 537                                 // Trim underscores
 538                                 .replace( rUnderscoreTrim, '' );
 539                 }
 540
 541                 // Process namespace prefix (if any)
 542                 m = title.match( rSplit );
 543                 if ( m ) {
 544                         id = getNsIdByName( m[ 1 ] );
 545                         if ( id !== false ) {
 546                                 // Ordinary namespace
 547                                 namespace = id;
 548                                 title = m[ 2 ];
 549                         }
 550                 }
 551
 552                 if (
 553                         namespace === NS_MEDIA ||
 554                         ( options.forUploading && ( namespace === NS_FILE ) )
 555                 ) {
 556
 557                         title = sanitize( title, [ 'generalRule', 'fileRule' ] );
 558
 559                         // Operate on the file extension
 560                         // Although it is possible having spaces between the name and the ".ext" this isn't nice for
 561                         // operating systems hiding file extensions -> strip them later on
 562                         parts = title.split( '.' );
 563
 564                         if ( parts.length > 1 ) {
 565
 566                                 // Get the last part, which is supposed to be the file extension
 567                                 ext = parts.pop();
 568
 569                                 // Remove whitespace of the name part (that W/O extension)
 570                                 title = parts.join( '.' ).trim();
 571
 572                                 // Cut, if too long and append file extension
 573                                 title = trimFileNameToByteLength( title, ext );
 574
 575                         } else {
 576
 577                                 // Missing file extension
 578                                 title = parts.join( '.' ).trim();
 579
 580                                 // Name has no file extension and a fallback wasn't provided either
 581                                 return null;
 582                         }
 583                 } else {
 584
 585                         title = sanitize( title, [ 'generalRule' ] );
 586
 587                         // Cut titles exceeding the TITLE_MAX_BYTES byte size limit
 588                         // (size of underlying database field)
 589                         if ( namespace !== NS_SPECIAL ) {
 590                                 title = trimToByteLength( title, TITLE_MAX_BYTES );
 591                         }
 592                 }
 593
 594                 // Any remaining initial :s are illegal.
 595                 title = title.replace( /^:+/, '' );
 596
 597                 return Title.newFromText( title, namespace );
 598         };
 599
 600         /**
 601          * Sanitizes a file name as supplied by the user, originating in the user's file system
 602          * so it is most likely a valid MediaWiki title and file name after processing.
 603          * Returns null on fatal errors.
 604          *
 605          * @static
 606          * @param {string} uncleanName The unclean file name including file extension but
 607          *   without namespace
 608          * @return {mw.Title|null} A valid Title object or null if the title is invalid
 609          */
 610         Title.newFromFileName = function ( uncleanName ) {
 611
 612                 return Title.newFromUserInput( 'File:' + uncleanName, {
 613                         forUploading: true
 614                 } );
 615         };
 616
 617         /**
 618          * Get the file title from an image element
 619          *
 620          *     var title = mw.Title.newFromImg( $( 'img:first' ) );
 621          *
 622          * @static
 623          * @param {HTMLElement|jQuery} img The image to use as a base
 624          * @return {mw.Title|null} The file title or null if unsuccessful
 625          */
 626         Title.newFromImg = function ( img ) {
 627                 var matches, i, regex, src, decodedSrc,
 628
 629                         // thumb.php-generated thumbnails
 630                         thumbPhpRegex = /thumb\.php/,
 631                         regexes = [
 632                                 // Thumbnails
 633                                 /\/[a-f0-9]\/[a-f0-9]{2}\/([^\s/]+)\/[^\s/]+-[^\s/]*$/,
 634
 635                                 // Full size images
 636                                 /\/[a-f0-9]\/[a-f0-9]{2}\/([^\s/]+)$/,
 637
 638                                 // Thumbnails in non-hashed upload directories
 639                                 /\/([^\s/]+)\/[^\s/]+-(?:\1|thumbnail)[^\s/]*$/,
 640
 641                                 // Full-size images in non-hashed upload directories
 642                                 /\/([^\s/]+)$/
 643                         ],
 644
 645                         recount = regexes.length;
 646
 647                 src = img.jquery ? img[ 0 ].src : img.src;
 648
 649                 matches = src.match( thumbPhpRegex );
 650
 651                 if ( matches ) {
 652                         return mw.Title.newFromText( 'File:' + mw.util.getParamValue( 'f', src ) );
 653                 }
 654
 655                 decodedSrc = decodeURIComponent( src );
 656
 657                 for ( i = 0; i < recount; i++ ) {
 658                         regex = regexes[ i ];
 659                         matches = decodedSrc.match( regex );
 660
 661                         if ( matches && matches[ 1 ] ) {
 662                                 return mw.Title.newFromText( 'File:' + matches[ 1 ] );
 663                         }
 664                 }
 665
 666                 return null;
 667         };
 668
 669         /**
 670          * Whether this title exists on the wiki.
 671          *
 672          * @static
 673          * @param {string|mw.Title} title prefixed db-key name (string) or instance of Title
 674          * @return {boolean|null} Boolean if the information is available, otherwise null
 675          */
 676         Title.exists = function ( title ) {
 677                 var match,
 678                         obj = Title.exist.pages;
 679
 680                 if ( typeof title === 'string' ) {
 681                         match = obj[ title ];
 682                 } else if ( title instanceof Title ) {
 683                         match = obj[ title.toString() ];
 684                 } else {
 685                         throw new Error( 'mw.Title.exists: title must be a string or an instance of Title' );
 686                 }
 687
 688                 if ( typeof match !== 'boolean' ) {
 689                         return null;
 690                 }
 691
 692                 return match;
 693         };
 694
 695         /**
 696          * Store page existence
 697          *
 698          * @static
 699          * @property {Object} exist
 700          * @property {Object} exist.pages Keyed by title. Boolean true value indicates page does exist.
 701          *
 702          * @property {Function} exist.set The setter function.
 703          *
 704          *  Example to declare existing titles:
 705          *
 706          *     Title.exist.set( ['User:John_Doe', ...] );
 707          *
 708          *  Example to declare titles nonexistent:
 709          *
 710          *     Title.exist.set( ['File:Foo_bar.jpg', ...], false );
 711          *
 712          * @property {string|Array} exist.set.titles Title(s) in strict prefixedDb title form
 713          * @property {boolean} [exist.set.state=true] State of the given titles
 714          * @return {boolean}
 715          */
 716         Title.exist = {
 717                 pages: {},
 718
 719                 set: function ( titles, state ) {
 720                         var i, len,
 721                                 pages = this.pages;
 722
 723                         titles = Array.isArray( titles ) ? titles : [ titles ];
 724                         state = state === undefined ? true : !!state;
 725
 726                         for ( i = 0, len = titles.length; i < len; i++ ) {
 727                                 pages[ titles[ i ] ] = state;
 728                         }
 729                         return true;
 730                 }
 731         };
 732
 733         /**
 734          * Normalize a file extension to the common form, making it lowercase and checking some synonyms,
 735          * and ensure it's clean. Extensions with non-alphanumeric characters will be discarded.
 736          * Keep in sync with File::normalizeExtension() in PHP.
 737          *
 738          * @param {string} extension File extension (without the leading dot)
 739          * @return {string} File extension in canonical form
 740          */
 741         Title.normalizeExtension = function ( extension ) {
 742                 var
 743                         lower = extension.toLowerCase(),
 744                         squish = {
 745                                 htm: 'html',
 746                                 jpeg: 'jpg',
 747                                 mpeg: 'mpg',
 748                                 tiff: 'tif',
 749                                 ogv: 'ogg'
 750                         };
 751                 if ( squish.hasOwnProperty( lower ) ) {
 752                         return squish[ lower ];
 753                 } else if ( /^[0-9a-z]+$/.test( lower ) ) {
 754                         return lower;
 755                 } else {
 756                         return '';
 757                 }
 758         };
 759
 760         /* Public members */
 761
 762         Title.prototype = {
 763                 constructor: Title,
 764
 765                 /**
 766                  * Get the namespace number
 767                  *
 768                  * Example: 6 for "File:Example_image.svg".
 769                  *
 770                  * @return {number}
 771                  */
 772                 getNamespaceId: function () {
 773                         return this.namespace;
 774                 },
 775
 776                 /**
 777                  * Get the namespace prefix (in the content language)
 778                  *
 779                  * Example: "File:" for "File:Example_image.svg".
 780                  * In #NS_MAIN this is '', otherwise namespace name plus ':'
 781                  *
 782                  * @return {string}
 783                  */
 784                 getNamespacePrefix: function () {
 785                         return getNamespacePrefix( this.namespace );
 786                 },
 787
 788                 /**
 789                  * Get the page name without extension or namespace prefix
 790                  *
 791                  * Example: "Example_image" for "File:Example_image.svg".
 792                  *
 793                  * For the page title (full page name without namespace prefix), see #getMain.
 794                  *
 795                  * @return {string}
 796                  */
 797                 getName: function () {
 798                         if (
 799                                 $.inArray( this.namespace, mw.config.get( 'wgCaseSensitiveNamespaces' ) ) !== -1 ||
 800                                 !this.title.length
 801                         ) {
 802                                 return this.title;
 803                         }
 804                         // PHP's strtoupper differs from String.toUpperCase in a number of cases
 805                         // Bug: T147646
 806                         return mw.Title.phpCharToUpper( this.title[ 0 ] ) + this.title.slice( 1 );
 807                 },
 808
 809                 /**
 810                  * Get the page name (transformed by #text)
 811                  *
 812                  * Example: "Example image" for "File:Example_image.svg".
 813                  *
 814                  * For the page title (full page name without namespace prefix), see #getMainText.
 815                  *
 816                  * @return {string}
 817                  */
 818                 getNameText: function () {
 819                         return text( this.getName() );
 820                 },
 821
 822                 /**
 823                  * Get the extension of the page name (if any)
 824                  *
 825                  * @return {string|null} Name extension or null if there is none
 826                  */
 827                 getExtension: function () {
 828                         return this.ext;
 829                 },
 830
 831                 /**
 832                  * Shortcut for appendable string to form the main page name.
 833                  *
 834                  * Returns a string like ".json", or "" if no extension.
 835                  *
 836                  * @return {string}
 837                  */
 838                 getDotExtension: function () {
 839                         return this.ext === null ? '' : '.' + this.ext;
 840                 },
 841
 842                 /**
 843                  * Get the main page name
 844                  *
 845                  * Example: "Example_image.svg" for "File:Example_image.svg".
 846                  *
 847                  * @return {string}
 848                  */
 849                 getMain: function () {
 850                         return this.getName() + this.getDotExtension();
 851                 },
 852
 853                 /**
 854                  * Get the main page name (transformed by #text)
 855                  *
 856                  * Example: "Example image.svg" for "File:Example_image.svg".
 857                  *
 858                  * @return {string}
 859                  */
 860                 getMainText: function () {
 861                         return text( this.getMain() );
 862                 },
 863
 864                 /**
 865                  * Get the full page name
 866                  *
 867                  * Example: "File:Example_image.svg".
 868                  * Most useful for API calls, anything that must identify the "title".
 869                  *
 870                  * @return {string}
 871                  */
 872                 getPrefixedDb: function () {
 873                         return this.getNamespacePrefix() + this.getMain();
 874                 },
 875
 876                 /**
 877                  * Get the full page name (transformed by #text)
 878                  *
 879                  * Example: "File:Example image.svg" for "File:Example_image.svg".
 880                  *
 881                  * @return {string}
 882                  */
 883                 getPrefixedText: function () {
 884                         return text( this.getPrefixedDb() );
 885                 },
 886
 887                 /**
 888                  * Get the page name relative to a namespace
 889                  *
 890                  * Example:
 891                  *
 892                  * - "Foo:Bar" relative to the Foo namespace becomes "Bar".
 893                  * - "Bar" relative to any non-main namespace becomes ":Bar".
 894                  * - "Foo:Bar" relative to any namespace other than Foo stays "Foo:Bar".
 895                  *
 896                  * @param {number} namespace The namespace to be relative to
 897                  * @return {string}
 898                  */
 899                 getRelativeText: function ( namespace ) {
 900                         if ( this.getNamespaceId() === namespace ) {
 901                                 return this.getMainText();
 902                         } else if ( this.getNamespaceId() === NS_MAIN ) {
 903                                 return ':' + this.getPrefixedText();
 904                         } else {
 905                                 return this.getPrefixedText();
 906                         }
 907                 },
 908
 909                 /**
 910                  * Get the fragment (if any).
 911                  *
 912                  * Note that this method (by design) does not include the hash character and
 913                  * the value is not url encoded.
 914                  *
 915                  * @return {string|null}
 916                  */
 917                 getFragment: function () {
 918                         return this.fragment;
 919                 },
 920
 921                 /**
 922                  * Get the URL to this title
 923                  *
 924                  * @see mw.util#getUrl
 925                  * @param {Object} [params] A mapping of query parameter names to values,
 926                  *     e.g. `{ action: 'edit' }`.
 927                  * @return {string}
 928                  */
 929                 getUrl: function ( params ) {
 930                         var fragment = this.getFragment();
 931                         if ( fragment ) {
 932                                 return mw.util.getUrl( this.toString() + '#' + fragment, params );
 933                         } else {
 934                                 return mw.util.getUrl( this.toString(), params );
 935                         }
 936                 },
 937
 938                 /**
 939                  * Whether this title exists on the wiki.
 940                  *
 941                  * @see #static-method-exists
 942                  * @return {boolean|null} Boolean if the information is available, otherwise null
 943                  */
 944                 exists: function () {
 945                         return Title.exists( this );
 946                 }
 947         };
 948
 949         /**
 950          * @alias #getPrefixedDb
 951          * @method
 952          */
 953         Title.prototype.toString = Title.prototype.getPrefixedDb;
 954
 955         /**
 956          * @alias #getPrefixedText
 957          * @method
 958          */
 959         Title.prototype.toText = Title.prototype.getPrefixedText;
 960
 961         // Expose
 962         mw.Title = Title;
 963
 964 }( mediaWiki, jQuery ) );